1. Field of the Invention
The present invention relates to a mobile communication control system, a mobile communication control method, a router, a server and a data structure.
2. Description of the Related Art
In a conventional IP (Internet Protocol) network, a “Mobile IP” technique for controlling a mobility of a mobility node (a mobile terminal), by transferring an IP packet destined for the mobility node to a home agent managing location information of the mobility node, and by encapsulating for transfer the IP packet destined for the mobility node from the home agent to the mobility node is proposed.
In the Mobile IP technique, the mobility node notifies a care of address used in a foreign network to the home agent, when the mobility node moves from a home network to the foreign network. The home agent holds a relationship between the care of address and a home address assigned to the home agent fixedly as binding cache information.
A correspondent node to the mobility node transmits the IP packet destined for the mobility node, using the home address fixedly assigned to the mobility node. The IP packet including the home address as a destination address is transferred to the home agent in the home network of the mobility node. The home agent encapsulates for transfer the IP packet transmitted from the correspondent node, using the care of address which is a current IP address of the mobility node.
In the Mobile IP technique, the communication route via the home agent is called a “triangle route”. To realize a “route optimization” for transferring the IP packet from the correspondent node to the mobility node directly without passing through the home agent, the mobility node can notify the care of address to the correspondent node and the correspondent node can transfer the IP packet to the mobility node directly using the care of address.
However, there is a problem in that downward communication from the correspondent node to the mobility node is performed through a route including the home agent in the hone network of the mobility node, so that the communication route becomes redundant (a triangle route) in the conventional Mobile IP technique.
There is a location privacy problem in that the correspondent node receives the care of address including the current location information of the mobility node when a system whereby the mobility node notifies the care of address to the correspondent node directly is used, that is, when a system for performing route optimization is used, so that the current location information is revealed to the correspondent node in the conventional Mobile IP technique.
There is a problem in that the care of address is used as a source address of the IP packet transmitted from the mobility node in upward communication from the mobility node to the correspondent node, the current location information of the mobility node is revealed to the correspondent node even when route optimization is not performed in the conventional Mobile IP technique.
There is a problem in that the home agent encapsulates the IP packet, so that an overhead of the IP packet increases in the conventional Mobile IP technique.
There is a problem in that an extended header is used when the IP packet is encapsulated in upward communication or downward communication using route optimization, so that an overhead of the IP packet increases in the conventional Mobile IP technique.
There is a problem in that the IP address of the home agent managing the current location information of the mobility node is notified to the mobility node in advance and the mobility node performs a location registration to the home agent in the home network directly, so that the IP address of the home agent managing and controlling the mobility of the mobility node can be revealed to an outsider and the home agent is vulnerable to unauthorized attacks in the conventional Mobile IP technique.